Last winter a third of US honeybees died. Should we be worried?

In the past six years, 10 million hives, worth $2bn, have been wiped out in the US. Last winter alone, a third of all US honeybees died. Should we be worried? John Hearne reports

IN her 2010 book, The Beekeeper’s Lament, American journalist Hannah Nordhaus describes the first instance of what has since become known as Colony Collapse Disorder, or CCD. It was December 2006. A Pennsylvanian beekeeper named Dave Hackenberg was tending bees overwintering in Florida.

“Hackenberg went to move 400 hives he had left on a gravel lot south of Tampa, and found 360 of them oddly empty. Full of honey, yes, and wax and honeycomb and brood-bees in various stages of development from egg to nearly imperceptible worm to white bee-like mass to baby bee.

“All that was left in most of them was a lonely, unattended queen and a clutch of attendants roaming the empty hives — just a pocketful, a cup of bees, not the teeming garbage-bin-sized load he expected. There were hardly any adult bees to be found. Nor could Hackenberg detect any sign of the opportunists who might under normal circumstances be expected to raid the honey stores of collapsed colonies: no robber bees, no wax moths, no hive beetles. There weren’t even any dead bees at the entrance to the hives. The entire adult population of the colony had simply flown out en masse and vanished.”

Three years after this book was written, and seven years after Hackenberg discovered his empty hives, researchers aren’t much closer to finding out what happened to his bees, or indeed any of the millions of bees that have disappeared in similar circumstances since then.

“No one can identify a cause,” says Dr Mary Coffey, a post-doctoral researcher at the University of Limerick. Each year for the past five, she had been working with the COLOSS network to survey the health and diversity of the bee population. “Scientists who have been studying it extensively say it’s a complex interaction of factors. Ok, Israeli Acute Bee Paralysis (IABP) is one of the viruses that has been found in all bees that have died with CCD, but it’s not the cause of their deaths. There’s no one factor. It’s a condition rather than a pest or anything like that.”

The plight of the bees isn’t unique. The grim reality of sharing a planet with humans is that thousands of species die out every year. According to the World Wide Fund for Nature, at least 27 different species wink out of existence every single day. Most are little known outside of academic journals.

The big deal about the honeybees is not their familiarity or the fact that humans have cultivated bees for thousands of years. It’s not even about the honey. It’s about the crucial role honeybees play in the human food chain. Albert Einstein is reported to have said that if the honeybee disappears from the face of the earth, man will only last four years without him.

While this may overstate the issue, the United States in particular is inordinately dependent on the honeybee. There, it’s estimated 130 different food crops rely heavily on honey bees for pollination. Moreover, these crops range across food types; apples, lemons, nuts, onions, carrots, leeks, broccoli mango, to name but a few.

Then there are the indirect impacts. Many honeybee pollinated crops end up in the animals which end up in us. In fact, the US Department of Agriculture has estimated that one out of every three mouthfuls eaten in the US is owed either directly or indirectly to honeybees.

Earlier this summer, Whole Foods Market, a US food chain which specialises in fresh produce highlighted this fact by emptying one of its stores of all the products which rely on the insect for pollination. The photos show half-empty displays almost completely devoid of colour. In total, they pulled 237 of 453 products from the shelves, amounting to more than half of the store’s entire stock.

The last century has of course transformed the business of farming in the US. In 1936, there were 6.8 million farms — today there are 2.2 million. Those small holdings gave way over a few short decades to a huge agri-industrial complex constructed around monocultures. Like any large-scale interference with the natural order, that process has thrown up a number of curiosities.

Take almonds for example. California’s production is worth €4 billion to the local economy, making it the state’s most important agricultural export, more than twice the value of its wine. And almonds are almost completely dependent on honeybees for pollination; without them, yields would not be one sixth of what they are with bees.

Every spring, thousands of beehives from all around the US are bussed into California to pollinate the crop. In fact, commercial bee keepers in the US make far more hiring out bees for pollination purposes than from their honey production. It’s a startling vulnerability, but it could be worse.

For a glimpse of a future without honeybees, check out the last year’s documentary More Than Honey from the Swiss director Marcus Imhoof. He went to China, where intensive farming and overuse of pesticides has so devastated bee populations in some regions that it is necessary for workers to pollinate fruit trees by hand.

Ever since Dave Hackenberg’s grim discovery in 2006, Colony Collapse Disorder has wrought devastation among bees across the globe, while the US in particular has remained particularly vulnerable. In the past six years, 10 million hives, worth some $2 billion have been wiped out. Last winter alone, a third of US honeybees perished, well over the 10% to 15% regarded as normal.

Here in Ireland, while there have been confirmed cases of CCD, it is nowhere as widespread as in the US. Which is not to say that the bee lives an untroubled life here. Far from it. Losses last winter were actually higher than in the US. Dr Coffey’s survey revealed that the bee population declined by 37% across the island. In some places, that figure was as high as 60%.

The consolation however is that in the main, Irish beekeepers know what’s happening. “Last summer was one of the worst ever.” Says Michael Gleeson, Honorary Secretary of the Federation of Irish Beekeepers’ Associations. “And that was compounded by a long, cold spring.”

That meant worker bees couldn’t find sufficient pollen to simulate the queen to lay, so there weren’t enough young bees to take over the duties of the older bees.

“Queen bees, when they’re mature, fly out and they’re mated by the drones on the wing, but because of the bad weather last year, they either didn’t get mated at all or weren’t properly mated.”

But it wasn’t just the weather.

Fifteen years ago, in 1998, a colony of bees was imported illegally into this country. Imports of honeybees were banned at the time because we were trying to keep the Varroa mite out of the country. This was, and is, a parasitic mite which attacks the honeybee in two ways. First by latching onto it and sucking its blood, then by vectoring a number of viruses that further weaken the host. What was notable about that 1998 colony is that it was the one that introduced the mite to Ireland.

Since then, it has spread throughout the country. Within a few years it had completely eradicated wild honeybees. And while treatments were developed to limit the mite’s destructive power in managed colonies, these treatments aren’t always effective. If, as happened last year, hives are already weakened by bad weather in the spring, they are doubly vulnerable to the predations of the mite.

The Varroa Destructor, as it’s known in the US, has been a focus for CCD researchers there for decades. But while there’s no denying its destructive power, Varroa’s modus operandi doesn’t square with the deserted hives which are the hallmark of collapse disorder.

Inevitably, pesticides have come under scrutiny, in particular a group of chemicals known as neonicotinoids. They are used in a variety of settings, including a number of garden sprays, and are particularly popular because they’re easier to handle than conventional pesticides. In one very popular application, seeds are treated with the chemical before planting. Then, as the plant grows, the chemical spreads through it, ending, ultimately, in its pollen and nectar.

“Because these neonicotinoids have been tested before being released, they don’t kill the bee directly,” says Mary Coffey in UL, “but it affects their ability to forage. Bees have two types of memory, vector memory and landscape memory, and they obviously need both of these to find their way home. If they receive too high a dose of this pesticide, they can’t find their way home and they get lost.”

The fact that bees leave the hive on routine foraging missions never to return has raised suspicions that neonicotinoids may be the whole problem. The timeline fits too. Widespread reports of colony collapse coincide with the widespread adoption of neonicotinoids. This is why they’ve been banned in the EU. Last April, a bill heavily backed by the European Food Safety Authority which sought a two year ban was supported by 15 of the 27 nations — Ireland abstained. Because the vote did not reach the qualified majority necessary to achieve automatic adoption, the decision then fell to the commission, who adopted the proposal in May. At the time, Health and Consumer Commissioner Tonio Borg said: “I pledge to do my utmost to ensure that our bees, which are so vital to our ecosystem and contribute over €22 billion annually to European agriculture, are protected.”

The ban has been as celebrated by environmental activists as it has deplored by the chemical companies who make neonicotinoids. Swiss agrichemical giant Syngenta and German chemicals group Bayer announced last month that they were taking the Commission to court over the ban.

They point to the fact that France continues to suffer bee losses despite having imposed restrictions on the use of these chemicals as far back as 1999. And the pesticides are also used in Australia, where, thus far, CCD has remained largely absent. So while there’s little doubt that neonicotinoids do damage honeybees, evidence that they actually cause CCD is circumstantial at best.

Here at home, the fact that we’re entirely surrounded by water has of course helped to limit the spread of the diseases and alien species that prey on bee populations on the continent. Thus far, Irish bees have been spared the attentions of the Asian Hornet, the world’s largest, which has been attacking European hives in greater numbers in recent years. Look them up on Youtube.

Twice the size of the honeybee, a band of t30 can wipe out a hive of honeybees in a matter of hours. They simply wait at the entrance to the hive and as the workers rush out to defend it, the hornets seize and kill them one by one.

The hornet has recently made its way from France to Belgium and the European Environmental Agency has said that it’s likely that the bee killer will soon arrive in the UK. Time will tell whether or not it will make it as far as these shores.

Though honeybee importation is now legal, beekeepers report that illegal imports continue. Aoife Nic Giolla Coda, a bee breeder and PRO of the Native Irish Honey Bee Society says that illegal bee imports have become a more significant problem now, than they were back when that Varroa-contaminated colony arrived in 1998. “It’s really exploded in the last two years,” she says.

The worry now is that further imports might introduce a Varroa mite resistant to the treatments that have, so far, limited its destructive power.

Beekeepers point out too that the disease American Foul Brood, which is one more thing American beekeepers have to contend with, is still quite rare here.

And another strain of the disease, European Foul Brood, is causing serious problems for beekeepers as close as southern England, but remains practically unknown in Ireland.

Beekeepers warn that if native queens become hybridised through mating with the drones of imported stock, the risk is that they will become more susceptible to these diseases.

Given all the risks, why does anyone risk bringing in non-native species? “There’s a misconception that native bees are not as productive,” says Nic Giolla Coda, “but that’s not actually true at all. Native bees are far more productive in our sparse summers than the more exotic sub species of honeybees.”

Other issues arise with imported bees. She describes a recent incident with a novice beekeeper who acquired Buckfast bees, which are called after the Catholic abbey in southern England where they were first bred — the same abbey which makes the familiar tonic wine.

“Beginners often have trouble with controlling their bees,” says Nic Giolla Coda.

“The novice’s two nucs (nucleus colonies) swarmed and when the new queens took over, they mated with the native drones in the locality. Their progeny became extremely aggressive. She couldn’t go within six feet of them.

“When you have two subspecies hybridising it can lead to very aggressive behaviour in the bees… The beekeeper just rang us in desperation to see if we would have queens so she could re-queen the hive because they had become so aggressive.”

This, says Nic Giolla Coda, is a common experience. She believes a total ban on imports, or at the very least, the imposition of strict controls is vital to preserve the integrity of native bee populations.

“At a more basic level, there should be legislation at least to protect the native honeybee strongholds because they are a very important genetic resource. There are resorts in certain parts of Europe, in Belgium, Holland and Switzerland where the honeybee is protected. If they have conservation areas there, we should be entitled to have conservation areas here. Otherwise, native bees will disappear. It’s only a matter of time.”

While farming has of course become considerably more intensive in this country over the past century, we have nothing to match the vast collectives and monocultures of the US.

We still have large tracts of countryside which provide everything the honeybee needs to thrive, and we are not dependent on the managed pollination programmes that keep the almond orchards of California in flower. Moreover, recent research suggests that all this fuss over the honeybee may actually be a little overdone.

Dr Jane Stout of the Department of Botany in Trinity College Dublin says honeybees aren’t as important pollinators as everyone thinks. “Yes, they are the most widely managed pollinator species — 90% of managed pollination worldwide is by honeybees — but recent work has found that wild bees, bumblebees and solitary bees, are as, or more, important for crop pollination.”

She points to a recent paper in the journal, Science, which found that wild insects actually pollinated crops more effectively than honeybees. The researchers found that an increase in wild insect visitation ‘enhanced fruit set (ie the degree to which a plant produces fruit after pollination) by twice as much as an equivalent increase in honey bee visitation.’

“So in terms of the impacts of honeybee decline,” says Stout, “if there are no wild pollinators left, then the impacts can be severe — for example in the almond orchards in California, but if there are still the wild pollinators as in Ireland, then the impacts will be less intense.”

There are in fact 101 species of bees in Ireland. Along with the one species of honeybee, there are 19 species of bumblebee and 81 species of other bee, most of which are solitary. All have suffered substantial declines since 1980, while over the past century, three have actually become extinct.

As far as the impact on the food chain goes, research has shown, as you would expect, that declines in pollinators lead to declines in the plants which they pollinate.

A recent study of bee and hoverfly populations in Britain and the Netherlands showed a strong casual connection between local extinctions of the pollinator and the plant it pollinated.

Closer to home, research from TCD on the impact of insect pollinators on strawberries has found that those unpaid workers were worth more than €10 million to the indoor strawberry industry in Ireland in 2010. Moreover, in the absence of insect pollinators, yields were lower, deformed fruit numbers were higher, while shelf life of the berries was also substantially reduced.

The good news for Irish beekeepers is that despite last winter’s devastation, subsequent good weather has prompted a complete reversal of fortune.

“When the weather came good from late may onwards,” says Michael Gleeson, “the bees literally turned inside out. It was as if you gave them a tonic. Not alone did they increase and multiply, they produced a reasonable crop of honey given that their numbers were quite low.”

Gleeson says that recession years have seen a huge increase in the take-up of beekeeping in Ireland. There are currently 2,850 beekeepers in the federation, more than double the number there was 15 years ago.

“Since the downturn, people have more time on their hands, they’re getting back to nature… Some people keep bees not for honey but for enjoyment, just to observe them working.”

Moreover, the traditional image of the elderly beekeeper no longer really applies. “I’m optimistic,” says Gleeson. “The future is bright. There are a lot of young people coming into beekeeping. In the past it was traditionally a hobby of elderly men. Now you’re getting a lot of women, and people with qualifications other than in beekeeping. That’s of great benefit.”